The invention relates to a trailer coupling for a motor vehicle, in particular a passenger car, comprising a base holder which can be or is securely mounted on the vehicle and further comprising a coupling arm at the free end of which a coupling element is arranged for coupling a trailer and which protrudes towards the rear from the motor vehicle in a position of use, wherein the coupling arm can be releasably secured to the base holder or is mounted movably between the position of use and a position of non-use in which it is moved towards the motor vehicle.
A trailer coupling for a motor vehicle for example comprises a fixed coupling arm to the free end of which a coupling element, for example a hitch ball, is attached. Apart from commonly found designs, in which the coupling arm is fixed, so-called detachable coupling arms which can be removed from the base holder if not in use, or coupling arms which are, for example, pivotably mounted on the base holder, so that they can be moved from a position of use, in which they protrude at the rear beyond a bumper of the motor vehicle, into a position of non-use, covered by the bumper, are commonly used as well.
Although such trailer couplings may be satisfactory for a multitude of applications, for example if a trailer is usually to be towed and rotatably mounted on the coupling element using a so-called tow ball coupling, difficulties are experienced if a load carrier is to be mounted on the spherical coupling element instead of a trailer. Load carriers can only be secured safely to the spherical coupling element by means of a complex clamping mechanism. Security against rotation nevertheless poses problems.
In addition, manufacturing costs for typical trailer couplings are relatively high, because each vehicle type as a rule requires an individual coupling arm which matches the geometrical design of the rear end of the motor vehicle. The base holder is generally mounted on a crossmember located behind the rear bumper, and the coupling arm has to extend backwards beyond the motor vehicle from the base holder on the rear bumper.